There are many different methods used to secure electrical boxes to the walls, floor or ceilings of a structure, such as a building. When studs are used to frame the structure, the most common method used is to secure the box directly to the stud. The advantage of this method is that installation is quick and simple. However, there is no guarantee that all the boxes installed in this fashion will be the same height off the floor and that they will be adequately supported. Also, there is no guarantee that all the boxes will be positioned at the same depth within the wall cavity. This is important so that any dry-wall ring or other device subsequently secured to the box will fit properly on the surface of the wall material.
When an extendable mounting bracket for an electrical box is required to span two adjoining studs that are not closely spaced together, it is often necessary to provide additional support for the bracket. This is especially true when more than one electrical box is mounted on the bracket and the weight of the boxes causes the bracket to flex and/or bend. Moreover, if the architectural plans call for the box or boxes to be mounted some distance from a stud, then methods requiring direct stud-mounting cannot be employed. In such cases, a bracket is required in order to support the box at some distance from the stud. There are basically two different types of brackets used for this type of application, either horizontal wall-mounted brackets or vertical floor-mounted brackets. In either case, once a particular electrical box size is selected and secured to the bracket, the installer is limited to using only a correspondingly sized dry-wall ring or other cover attachment.
Many different designs of floor-mounted and wall-mounted brackets are known and they typically are designed for mounting vertically with one end attached to the sole plate of a wall or between studs with standard center-to-center dimensions. Therefore, a user may have to stock several different sizes of brackets to accommodate different center-to-center dimensions. This is an added expense for the user. Moreover, when a bracket is mounted between studs having non-standard center-to-center dimensions, the user may have to add additional framing before he can install the bracket. Adjustable brackets that have been used in the past do not have the strength and rigidity of non-adjustable brackets and, therefore, have not been widely used. Moreover, brackets that span long distances may flex and bend easily and so they require additional far-side support.
Accordingly, it is an object of the present invention to provide a bracket (which can be either floor-, wall- or ceiling-mounted) for mounting electrical boxes between structural supports within the walls, floor or ceilings of a building that overcomes this deficiency. One object of this invention is to provide an adjustable mounting bracket assembly that is simple in construction and easy to install between studs having a variety of different center-to-center dimensions. Another object of this invention is to provide an adjustable mounting bracket assembly that has adequate strength and rigidity for supporting one or more electrical boxes and a far-side support between the ends of the bracket that are attached to the structure.